title: Influence of barley variety, timing of nitrogen fertilisation and sunn pest infestation on malting and brewing.
abstract: BACKGROUND
  This paper presents a multivariate approach to investigate the influence of barley variety, timing of nitrogen fertilisation and sunn pest infestation on malting and brewing. Four spring and two winter barley varieties were grown in one location in southern Europe. Moreover, one of the spring varieties was infested with sunn pest, in order to study the effects of this pest on malting quality, and subjected to different nitrogen fertilisation timing regimes. The samples were micromalted, mashed, brewed and analysed.
  
  
  RESULTS
  The data showed that even though the two winter barleys seemed to be the best regarding their physical appearance (sieving fraction I + II > 82%), this superiority was not confirmed in the malt samples, which showed low values of Hartong extract (27.1%) and high values of pH (6.07-6.11) and β-glucan content (12.5-13.2 g kg(-1)), resulting in low-quality beers. The barley sample subjected to postponed fertilisation had a total nitrogen content (19.5 g kg(-1) dry matter) exceeding the specification for malting barley and gave a beer with a low content of free amino nitrogen (47 mg L(-1)) and high values of viscosity (1.99 cP) and β-glucan content (533 mg L(-1)). The beer obtained from the barley sample subjected to pest attack had good quality parameters.
  
  
  CONCLUSIONS
  All spring barleys gave well-modified malts and consequently beers of higher quality than the winter barleys. Moreover, postponed fertilisation was negatively related to the quality of the final beer, and sunn pest infestation did not induce important economic losses in the beer production chain.
authors.affiliation: Department of Economic and Food Science, University of Perugia, Via San Costanzo, I-06126 Perugia, Italy. omarconi@unipg.it
authors.forename: Ombretta
authors.initials: O
authors.lastname: Marconi
authors.forename: Valeria
authors.initials: V
authors.lastname: Sileoni
authors.forename: Michele
authors.initials: M
authors.lastname: Sensidoni
authors.forename: José Manuel Amigo
authors.initials: JM
authors.lastname: Rubio
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Perretti
authors.forename: Paolo
authors.initials: P
authors.lastname: Fantozzi
mesh_terms: D000818:Animals; D001515:Beer / Q000032:analysis* / Q000592:standards; D002523:Edible Grain; D005060:Europe; D005308:Fertilizers; D001467:Hordeum / Q000737:chemistry* / Q000145:classification; D006863:Hydrogen-Ion Concentration; D007313:Insecta; D009584:Nitrogen / Q000008:administration & dosage*; D010935:Plant Diseases; D013045:Species Specificity; D047071:beta-Glucans / Q000032:analysis
chemical_list: D005308:Fertilizers; D047071:beta-Glucans; D009584:Nitrogen